Why does stomatal closure not affect breathing?

Stomatal is a small opening on the epidermis of plant leaves, which is used for gas exchange and ventilation, and can regulate water transpiration, gas absorption and emission of plants. In photosynthesis, carbon dioxide enters plant leaves through stomata, and oxygen is discharged through stomata. Therefore, the opening and closing of stomata directly affects the photosynthesis of plants.

However, even if the stomata are closed, the respiration of plants can still be carried out. Respiration is a biochemical process in plant cells, which is used to generate energy and convert organic matter into carbon dioxide and water. The main function of stomata is to regulate gas exchange and water transpiration of plants. During photosynthesis, stomata are opened, carbon dioxide enters, oxygen is discharged, and water transpiration occurs. In dark or dry environment, stomata will be closed to reduce water transpiration and protect plants from excessive water loss.

Although stomatal closure will reduce the gas exchange and water transpiration of plant leaves, the respiration of plants can continue. This is because there are many organelles in plant cells, such as mitochondria, in which they breathe. Breathing needs oxygen and organic matter, and oxygen can directly enter the cell through the cell membrane, independent of the opening and closing of stomata.

To sum up, stomatal closure will not affect the respiration of plants, because respiration occurs inside cells, and stomata mainly regulate photosynthesis and water transpiration.